Social inequalities are an important predictor of disease incidence, including cancer. Persons with low socioeconomic status (SES) have increased rates of lung and other tobacco-related cancers. Although smoking prevalence is higher in persons with lower levels of education and occupational status, smoking prevalence does not explain this excess risk. In prospective cohort studies, the associations between low SES and elevated lung cancer risk persist after adjustment for smoking amount and duration. The investigators'overall hypothesis is that the unaccounted increased risk in populations with lower SES is due to higher smoke exposure that cannot be accounted for by self-reported smoking habits. Their previous laboratory studies demonstrate that there is a wide degree of variation in biological exposure to tobacco smoke toxins and carcinogens per cigarette smoked. The investigators propose to conduct a community-based participatory study in the medically underserved area of Appalachian Pennsylvania to determine the relationship between SES and the dose of inhaled mainstream smoke and the dose of biological markers of tobacco smoke exposure. Specific aims are: Specific Aim 1. Determine whether SES is associated with smoking puffing behaviors including puff volume, duration, interval, and length of cigarette smoked. Specific Aim 2. Determine whether SES is associated with biomarkers of smoking exposure including salivary cotinine and expired carbon monoxide. This addresses the SES hypothesis using biological measures of dose in addition to environmental measures such as puffing dose. Specific Aim 3. Correlate environmental and biological measures of smoke exposure. This aim will determine whether levels of mainstream smoke exposure, as estimated by puffing profiles are determinants of the biological levels of cigarette smoke exposure, and whether this relationship differs by SES. This brings together aims 1 and 2 to comprehensively address the SES hypothesis. Specific Aim 4. Determine the effects of psychological stress, as assessed by psychological scales and salivary stress biomarkers, on smoking puffing parameters and salivary cotinine levels. The proposed research study will be conducted in Appalachia, Pennsylvania (PA), a NIH-designated medically underserved but socioeconomically diverse population. The investigators predict that lower SES is associated with higher smoke intake as determined by topography and smoke biomarkers, and that this finding will help to explain the long-observed patterns of lung cancer incidence disparities. PUBLIC HEALTH RELEVANCE: A major objective of cancer control efforts is to understand the causes of social inequalities in cancer rates. Cigarette smokers of lower socioeconomic status (SES) have increased rates of lung cancer and other tobacco-related diseases than smokers of higher SES. Because smoking is a modifiable behavior, findings that demonstrate more intensive smoking and greater exposure to tobacco smoke among low SES smokers may be helpful in developing more effective and targeted smoking control efforts.